Support is requested for a scientific meeting organized by the American Association for Cancer Research, Inc. (AACR). The conference is entitled "Negative Controls on Cell Growth and Their Breakdown during the Pathogenesis of Cancer" and will be held at the Chatham Bars Inn in Chatham, Massachusetts, on October 20-24, 1991. The Organizing Committee for this conference consists of Drs. Robert A. Weinberg, Chairperson; Arnold J. Levine, David M. Livingston, and Eric J. Stanbridge. The invited speakers are well-known investigators in this field. They will make 30- to 60-minute presentations. Approximately 150-175 other conference registrants will have the opportunity to present their own novel work during poster sessions. The major goals of the conference are the presentation of the latest discoveries in the areas of the molecular origins of cancer, negative growth controls, and tumor suppressor genes. While oncogenes act positively on cell growth, a diverse group of genes may act to repress or constrain cell growth. These growth-suppressing genes may become involved in tumor pathogenesis when they become inactivated. Once a cell is deprived of the services of one or more such genes, it may no longer be able to respond appropriately to the signals that would, in the context of normal tissue, dictate the shutdown of its growth. Accordingly, the end product of this gene inactivation may be very similar to that seen upon the deregulation of proto-oncogenes. Indeed, since gene inactivation is more readily achieved through random mutations than this deregulation/activation, it may well be the case that the inactivations of such genes play a more important role in cancer pathogenesis than the activation of oncogenes. For these reasons, the field of negative controls on cell growth will assume increasing importance in the ensuing years and by mid-decade will likely attract as much research interest as the oncogenes. Participants will be drawn from a variety of scientific areas and all levels of training from graduate students to senior basic scientists or clinical investigators. The conference will provide substantial opportunities for both formal and informal scientific exchange among all participants and speakers. It is anticipated that this exchange will enrich current research and suggest new conceptual insights into the rapidly developing field of negative growth control.